Acute transverse myelitis in a 15-month-old girl: report of a case with MRI findings.

A 15-month-old girl demonstrated progressive weakness in all limbs. Magnetic resonance imaging (MRI) on admission revealed (1) diffuse and symmetric cervical cord swelling, (2) diffuse decrease and increase in signal intensity within the affected cord on T1- and T2-weighted images, respectively, (3) preserved anatomic structure of gray and white matter of the cord, and (4) lack of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhancing effect. She showed rapid clinical improvement in response to steroid therapy, and repeat MRI showed marked reduction in the degree of cord swelling and abnormal signal intensity. Based on the above clinical and MRI findings, the diagnosis of acute transverse myelitis was made. Although various pathologic conditions also could produce similar cord swelling and abnormal signal intensity on MRI, the third and fourth findings mentioned above suggested that the lesion was inflammatory rather than neoplastic. Our case indicates that MRI may be informative in differentiating acute transverse myelitis from other intramedullary disorders.